Hepatocellular Necrosis, Apoptosis, and Proliferation after Transcatheter Arterial Embolization or Chemoembolization in a Standardized Rabbit Model

Purpose: To evaluate the effect of transcatheter arterial chemoembolization versus transcatheter arterial embolization on hepatocellular damage, apoptosis, proliferation, and proinflammatory response in a rabbit VX2 tumor model. Materials and Methods: Rabbits implanted with VX2 tumors in left liver lobes were randomly divided into three groups: a control group (n = 9) that underwent infusion of distilled water into the left hepatic artery, an embolization group (n = 15) that underwent left hepatic artery embolization with polyvinyl alcohol (PVA) particles, and a chemoembolization group (n = 15) that underwent left hepatic artery infusion of a mixture of 10-hydroxycamptothecin and iodized oil followed by PVA embolization. Serum and liver samples were collected at 6 hours, 3 days, and 7 days postoperatively. Liver damage was measured by liver function tests and histologic analysis. Ki-67 immunohistochemistry and terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick-end labeling were performed to quantify proliferating and apoptotic cells. Serum tumor necrosis factor (TNF)-alpha levels were measured to assess proinflammatory response. Results: Compared with embolization, chemoembolization caused liver injury with a greater increase in serum alanine aminotransferase and aspartate aminotransferase levels on days 3 and 7; histologic analysis showed increased hepatic necrosis in adjacent liver tissue beginning at day 3 and increased serum levels of TNF-alpha at 6 hours. By contrast, chemoembolization resulted in a slower increase in hepatocyte proliferation. Additionally, increased apoptotic hepatocytes were observed after embolization and chemoembolization. Conclusions: In contrast to embolization, nonsuperselective transcatheter arterial chemoembolization increased hepatocellular damage and stimulated systemic proinflammatory cytokine release, but inhibited hepatocyte proliferation.